Code review for bug fix 8025741

[Bhavesh Patel]

Hi,
   There is a bug in jdk/make/docs/Makefile for JDK8. The bug is listed at https://bugs.openjdk.java.net/browse/JDK-8025741. The Makefile for JDK 8 does not include the DEV_DOCS_URL that should point to the developer documentation URL for JDK 8. This creates an empty href in <a> HTML tag resulting in tidy warnings in the generated JDK API documentation.
   I have fixed the Makefile to include the variable and have pointed it to the JDK 8 developer documentation URL. The webrev for the fix it at http://cr.openjdk.java.net/~bpatel/8025741/webrev.00/.

Thanks,
Bhavesh.